Excessive Tension Research Articles

Leveraging Microneedles for Raised Scar Management.

Disruption of the molecular pathways during physiological wound healing can lead to raised scar formation, characterized by rigid, thick scar tissue with associated symptoms of pain and pruritus. A key mechanical factor in raised scar development is excessive tension at the wound site. Recently, microneedles (MNs) have emerged as promising tools for scar management as they engage with scar tissue and provide them with mechanical off-loading from both internal and external sources. This review explores the mechanisms by which physical intervention of drug-free MNs alleviates mechanical tension on fibroblasts within scar tissue, thereby promoting tissue remodeling and reducing scar severity. Additionally, the role of MNs as an efficient cargo delivery system for the controlled and sustained release of a wide range of therapeutic agents into scar tissue is highlighted. By penetrating scar tissue, MNs facilitate controlled and sustained localized drug administration to modulate inflammation and fibroblastic cell growth. Finally, the remaining challenges and the future perspective of the field have been highlighted.

Tröger's base-embedded macrocycles with chirality.

The birth and development of supramolecular chemistry have heralded a new era, where macrocycles have become an irreplaceable research tool. Therefore, the construction of novel macrocycles has become a hot spot. Tröger's base (TB), as a fragment with both rigidity and chirality, promises tremendous potential in the realm of supramolecular chemistry, and its unique properties continue to motivate researchers to explore its inclusion in macrocycles. However, the construction of a TB-embedded macrocycle is always difficult due to the frequent occurrence of excessive tension. For successful synthesis, part of the function of TB in macrocycle is often overlooked or sacrificed to facilitate the macrocyclization process, leading to serious deficiencies in the utilization of the functions of TB. Thus, the research on TB-embedded macrocycles is still in its preliminary stage. Hence, in this review, TB-embedded macrocycles are highlighted, focusing not only on the linkers of these macrocycles but also on the correlation between the properties of TB and TB-embedded macrocycles. We hope that this review will further guide the synthesis of more excellent macrocycles.

Assessing the impact of sewing machine thread take-up mechanism parameters on the magnitude and nature of thread take-up

The subject of this study is the needle thread take-up mechanisms (NTТM) of modern chain stitch sewing machines of classes 400 and 600. The principal issue with these mechanisms is the complexity of their adjustment because of the large number of adjustable parameters and the need for clear recommendations for proper setup, which negatively affects their performance. The research involved analyzing the impact of NTTM’s kinematic parameters and various thread path configurations in machines. The study revealed new patterns that allow for more precise thread take-up regulation, enabling better synchronization of the actual thread take-up with the required amount, thereby improving stitch quality and increasing sewing process productivity. Accurate thread take-up adjustment prevents excessive or insufficient thread tension, a common issue when sewing materials with variable thickness or stitch length. The results can be used to adjust sewing machines and automate the tuning of technological processes by changing the adjustment parameters with variations in technological parameters. This is particularly important in producing 3D textile structures for reinforcing composite molds, where adjusting for average material thickness can cause thread tension issues when the current thickness changes. The practical application of these results will ensure stable sewing quality based on stitch parameters, which is relevant for automating machine settings and working with materials of varying thicknesses. The proposed recommendations will improve the manufacturing process and increase equipment efficiency

Reconstruction of radial deviation after preaxial polydactyly surgery: use of an ulnar fascial flap.

Radial deviation of the interphalangeal (IP) joint is a common complication of treating Wassel type IV-D preaxial polydactyly. Long-term radial deviation can place excessive tension on the radial skin and cause overabundance of the ulnar skin. To overcome this problem, we aimed to utilize a fascial flap for ulnar reconstruction of a defect in the radial skin. We used a fascial flap for ulnar reconstruction of a defect in the radial skin, eight patients (average: 12 years, range: 5-33 years) who underwent reconstructive surgery at our department for radial deviation of the interphalangeal (IP) joint after the initial operation were included between August 2017 and August 2021. An incision was made on the radial side of the thumb. An olive-shaped flap was designed on the ulnar eminence of the IP joint. The skin and fascia in the other three quadrants were incised. While the flap was protected, children with epiphyseal plates underwent wedge osteotomy at the maximum ulnar deviation of the proximal phalanx, and adults underwent direct fusion of the distal IP joint. Absorbable sutures were used to suture the flap. The Tada functional and visual analog scale (VAS) scores were recorded before and after the operation. All flaps survived without infection or necrosis. The preoperative and postoperative Tada scores were 1 and 5, respectively, and the preoperative and postoperative VAS scores were 3 and 9, respectively. The postoperative scores showed a statistically significant degree of improvement. An ulnar fascial flap is an effective and feasible option for repair of radial deviation following surgery for preaxial polydactyly.

The Double-Edged Sword of Tension: How Moderate Stress Enhances Performance While Over-Focus Impairs It

Tension, often considered a negative emotional state, has traditionally been viewed as detrimental to performance, particularly when excessive. However, emerging research suggests that tension, when experienced at moderate levels, may have a facilitating effect on task performance by activating physiological and cognitive resources. This study explores the dual effects of tension on behavioral outcomes, proposing that moderate tension improves performance by enhancing arousal and resource mobilization, while excessive focus on tension can lead to cognitive overload, impairing task performance. Two hypotheses are tested: (H1) moderate tension enhances task performance through physiological arousal mechanisms such as increased adrenaline secretion, and (H2) excessive focus on tension increases cognitive load, leading to poorer performance. A randomized experimental design will be employed, with participants assigned to a moderate tension group, an excessive tension focus group, and a control group. Physiological measures, including heart rate and galvanic skin response (GSR), along with task performance indicators, will be collected. The expected results will provide empirical evidence supporting the positive role of moderate tension in enhancing behavioral outcomes and highlight the detrimental effects of excessive tension focus. This study offers theoretical insights into the dual nature of tension and practical implications for managing tension in high-pressure task environments.

Papilla Access Tunnel Combined With the Laterally Closed Tunnel: A Technique for Treatment of Deep Gingival Recession in the Anterior Mandible.

Treatment of gingival recession in the anterior mandible is more complex due to unique anatomic features including excessive tension due to frenal and muscle attachments, thin tissue, shallow vestibule, and narrow interdental space. These features are particularly limiting in the presence of deep recession and negatively impact the success most routine soft tissue grafting procedures. The recently proposed laterally closed tunnel combined the benefit of tension management from tunneling rather than incising papillae with lateral closure of deep recession to minimize the need for coronal advancement. This is an effective, although technically demanding procedure. This report presents a method of facilitating tunnel preparation by utilizing superficial papillary access incisions bilaterally in the papilla between the lateral incisor and canine. This papilla has the least tension and most robust interdental volume and blood supply. This incision creates a mini flap that facilitates tunnel dissection and graft placement. Because the mini flap is used for graft insertion, the suturing for lateral closure can be performed before graft insertion. The result is reduced technical difficulty.

Temporary loop end ileostomy reduces the risk of stoma outlet obstruction: a comparative clinical study in patients undergoing restorative proctocolectomy and ileal pouch-anal anastomosis.

Stoma outlet obstruction (SOO) is a serious complication of restorative proctocolectomy (RPC) and ileal pouch-anal anastomosis (IPAA). When the ileal mesentery to the pouch is under excessive tension, the ileum near the ileostomy twists easily, causing SOO. Loop-end ileostomy (EI) for fecal diversion was introduced in 2021 to prevent SOO, and we aimed to verify whether temporary EI reduces the incidence of SOO in RPC and IPAA patients relative to loop ileostomy (LI). This study included 106 consecutive RPC and IPAA patients with a diverting ileostomy and categorized them into LI (n = 75) or EI (n = 31) groups. The clinical characteristics of the patients were analyzed and compared. Patient characteristics were similar between the groups, except for higher preoperative steroid use in the LI group (38.7%; p = 0.0116). There were no significant differences between the groups in anatomical factors, such as abdominal wall thickness and the height-adjusted distance between the root of the superior mesenteric artery and the bottom of the external anal sphincter. There were no significant differences in surgery-related factors, with ≥ 90% of the patients in each group undergoing laparoscopic procedures. A multivariate logistic regression analysis revealed that EI significantly reduced the risk of SOO relative to LI (OR, 0.18; 95% CI 0.03-0.92; p = 0.0399). EI reduced SOO levels after RPC and IPAA and may be beneficial for cases in which anastomosis is challenging.

Clinical application of myofascial therapy in the treatment of postpartum pain-related functional disorders: A review.

During pregnancy, fetal growth could lead to changes in human biomechanics. If postpartum recovery was not properly managed, it could be exacerbated, resulting in myofascial system disorders and various functional impairments. Among them, pain-related functional disorders were an important issue affecting quality of life in postpartum women. The pathogenesis of these disorders remained unclear but it was primarily associated with changes in biomechanics, the endocrine system, and nervous function. However, postpartum pain-related dysfunction had been considered a normal physiological response to childbirth, leading to a lack of attention. Therefore, many postpartum women failed to receive timely, effective, and standardized treatment, hindering their ability to reintegrate into family and society, and causing severe damage to their physical and mental health. In clinical practice, myofascial therapy could effectively alleviate postpartum pain and muscle spasms, improve excessive tension injuries in myofascial, and had a good therapeutic effect on postpartum pain-related functional disorders. The mechanism of myofascial therapy involved improving core muscle strength, restoring normal body alignment, and promoting the remodeling of myofascial mechanical structures. This article explored the positive effects of myofascial therapy on postpartum pain-related functional disorders from a biomechanical perspective, aiming to provide diverse treatment approaches for clinical practitioners.

Scalp defect associated with extensive fibrosis of artificial dura requiring modified closure

Background A variety of methods are available for scalp defect closure and necessitate extensive planning. Superficial temporal artery (STA) based local flaps are widely used in the field of scalp and face reconstruction because of their flexibility and rich vascularity. Rotation and transposition techniques are commonly used in the area, however at times result in excessive tension. V-Y advancement allows tension-free closure with reduced post-operative complications. Case presentation A case of scalp defect post multiple craniectomies for a traumatic head injury complicated with subgaleal collection and poor wound healing in a 29-year-old male, is reported. Due to the nature of defect, with underlying fibrosis and previous artificial duraplasty, along with location in the frontotemporal region, a local STA based flap closed in a rotation, transposition and unilateral V-Y advancement pattern was used. Conclusion The challenges encountered in wound closure of complicated post-traumatic and multiple craniectomy cases can be overcome with a modified combined approach which achieves optimal wound closure. Bangladesh Journal of Medical Science Vol. 23 No. 04 October’24 Page : 1227-1232

A Modified Epiglottis-Tongue Root Flap for Postoperative Laryngeal Stenosis in a Cancer Patient with a History of Radiotherapy

Introduction: Cricohyoidoepiglottopexy (CHEP) has emerged as a promising surgical technique for treating laryngeal stenosis, offering a low rate of restenosis and a high rate of successful decannulation. However, postoperative radiation therapy can complicate open surgery for some patients due to radiation-induced cellular and tissue damage. This damage can make adequate exposure or mobilization of the larynx challenging. Case Summary: A 71-year-old male, who had undergone a partial laryngectomy 3 years prior, developed laryngeal stenosis and difficulty plugging after 35 rounds of radiotherapy. Initially, CHEP was planned, but intraoperatively, it was found that traditional CHEP would result in excessive anastomotic tension. To prevent complications, we designed an epiglottis-tongue root flap for laryngeal function reconstruction. The patient experienced no restenosis and was successfully extubated. Discussion: By separating the preepiglottal space and mobilizing the base of the tongue to construct the epiglottis-tongue root flap, modified CHEP can achieve laryngeal function reconstruction in patients postradiotherapy. It is essential to conduct a comprehensive evaluation of the patient’s overall condition, degree of stenosis, tongue-to-tongue root status, and cervical tissue adhesion before surgery.

A NOVEL FOUR-POINT SCLERAL FIXATION TECHNIQUE WITH A HYDROPHOBIC INTRAOCULAR LENS: The Loop to Optic and Trailing end to Outside Technique.

To describe a new surgical technique that combines four-point, flanged polypropylene scleral fixation with a hydrophobic intraocular lens (IOL). Using the Envista MX60 and 6.0 polypropylene, scleral four-point fixation was achieved using a flanged-suture technique five times in a model eye and in a case series of eight patients, retrospectively reviewed. The polypropylene is passed through each eyelet in a novel configuration Loop to Optic and Trailing ends to Outside. Conjunctival peritomies, scleral flaps/pockets, glue, and suture knots are avoided. The load needed for haptic fracture and scanning electron microscopy at fracture sites were studied. Haptic fracture occurred once following the first model eye implantation due to excessive suture tension. The fracture load was similar between the Loop to Optic and Trailing end to Outside and the simple-pass technique (1.08 ± 0.52 N vs. 1.09 ± 0.32 N), suggesting no safety compromise. Scanning electron microscopy did not disclose the cheese-wiring effect. Over a mean follow-up of 10.8 months (range: 3-19; median 11.5 months), all cases experienced visual improvement with best-achieved-postoperative uncorrected visual acuity of 20/25 to 20/200, and the IOL was well-centered. Postoperative IOL tilt averaged 2.9° (range: 0-9.6; median: 2.9°). Two patients developed postoperative cystoid macular edema treated topically. The first case developed flange extrusion that was readily repaired in the clinic. This novel technique adds two main advantages to previously described flanged-suture techniques: 1) four-point fixation of a hydrophobic IOL; 2) immediate application at the time of initial complicated cataract surgery because it requires no additional supply, IOL, or instrumentation.

Agmatine Improves Oxidative Stress Profiles in Rat Brain Tissues Induced by Sodium Azide

Introduction: The brain is highly susceptible to oxidative damage due to excessive oxygen tension, a high concentration of oxidizable substrates, and low antioxidant capacity. Consequently, oxidative stress is linked to several brain disorders and neurodegeneration. Sodium azide is a cytochrome oxidase inhibitor that promotes neurodegeneration by enhancing the release of excitotoxins and inducing oxidative stress through the peroxidation of membrane lipids. This process results in the release of intra-mitochondrial Ca+2 and H2O2 (ROS Dependent-Ca+2 release). Agmatine, a biogenic amine, is also referred to as a free radical scavenger, protecting the brain from membrane collapse, apoptosis, and mitochondrial swelling. Objective: This study was designed to identify the antioxidative effects of agmatine on sodium azide- induced oxidative stress in brain tissues. Methodology: Twenty-four male albino Wistar rats were allocated into two groups: a control group receiving water and a test group administered sodium azide (5 mg/kg, intraperitoneally) for a duration of 14 days. Subsequently, the animals were further subdivided and treated for an additional two weeks with either water or agmatine (100 mg/kg). Behavioral assessments were performed onehour post-agmatine administration, and brain homogenates were prepared for biochemical analyses. Results: The agmatine-treated group exhibited a significant increase (P<0.01) in both the number of entries and the time spent in the light box and the open arms of the light/dark transition box and elevated plus maze tests, respectively. Additionally, agmatine administration significantly enhanced (P<0.01) the total number of squares crossed in the open field test. Biochemical assessments revealed that agmatine treatment significantly reduced (P<0.01) the levels of reactive oxygen species and malondialdehyde. Moreover, it significantly increased (P<0.01) the levels of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) and glutathione compared to the control group. Conclusion: The present study revealed that agmatine has substantial effects on oxidative and antioxidant enzyme levels in sodium azide-induced oxidative stress. Agmatine-treated rats exhibited decreased reactive oxygen species levels and improvements in behavioral impairments resulting from sodium azide administration.

353. INNOVATIVE SURGICAL TECHNIQUES TO REDUCE RECURRENCE IN LAPAROSCOPIC RADICAL TREATMENT OF GIANT HIATAL HERNIA

Abstract Background In Japan, there is an increasing trend in the number of esophageal hiatal hernia (EHH) surgeries performed in elderly patients. EHH in the elderly patients are associated with surgical invasiveness and complications, but safe surgery can contribute to improving quality of life (QOL). We report on the safe surgical technique and treatment results for giant hiatal hernia. Methods The most important point to be careful of when suturing the esophageal hiatus is damage to the diaphragm leg. If the esophageal hiatus is large, reducing the pneumoperitoneum pressure as much as possible will reduce the tissue resistance during suturing, allowing suture closure without placing excessive tension on the diaphragm legs. If the esophageal hiatus is large, the pneumoperitoneum pressure should be kept as low as possible to reduce tissue resistance during suturing and prevent damage to the diaphragm legs. Surgery is usually performed with a high pneumo-abdominal pressure of 10 mmHg, but if suture closure of the esophageal hiatus is difficult, suturing is performed with a low pneumo-abdominal pressure of 6 mmHg. We underwent 103 cases of EHH surgery between 2012 and 2022. There were 73 cases (70.8%) of over 75 years old patients, and 71 cases (68.9%) of giant mixed type EHH. We compared the surgical outcomes in the early group up to 2018, in which surgery was performed with high pneumo-abdominal pressure during hiatal closure, and the latter group, from 2019 onwards, in which surgery was performed with low pneumo-abdominal pressure during hiatal closure. Results 67 cases in the early group: 23 cases with sliding type/44 cases with mixed type (65.6%), 36 cases in the latter group: 8 cases with sliding type/27 cases with mixed type (75.0%), the proportion of mixed type was higher in the late group. Mesh was used in 1 case in the early group and 0 cases in the latter group. The recurrence rate was 7 cases (10.4%) in the early group and 1 case (2.8%) in the late group, and although the proportion of mixed type cases was higher in the latter group, the recurrence rate was lower. Reoperation for recurrence was performed in 1 patient in the early group. In one case of recurrent surgery in the early group, the type of recurrence was that the muscle bundle of the diaphragm leg on one side was torn, the hiatus was dilated, and the transverse colon was invaginated into the mediastinum. From this experience, I reaffirmed the importance of reliably suturing the esophageal hiatus without damaging tissue in order to reduce recurrence of giant hiatal hernia surgery. Although there are differences in observation periods, in recent years, appropriate management of intraoperative pneumoperitoneum pressure has been able to reduce recurrence and complications, and it has also been possible to safely improve QOL in elderly patients. Conclusions In giant hiatal hernia surgery, appropriate control of intraoperative pneumoperitoneum pressure can reduce recurrence.

Experimental determination and theoretical modeling of isobaric vapor–liquid equilibria, liquid mass density, surface tension and dynamic viscosity for the methyl butyrate and tert-butanol binary mixture

The purpose of this work is to provide consistent experimental measurements on the vapor–liquid equilibria (VLE) at the isobaric conditions of 50.00, 75.00 and 94.00kPa, as well as experimental determinations of the liquid mass densities, the surface tensions and the dynamic viscosities at 298.15K and 101.3kPa of the methyl butyrate + tert-butanol binary system within the whole composition range. For these goals, a Gillespie-type cell is used to carry out the VLE measurements, whereas an oscillating densimeter, a maximum differential bubble pressure tensiometer, and a rotating viscometer are used to quantify the remaining physical properties. The thermodynamical quality of the reported VLE data is validated by Fredenslund’s consistency test. Based on the VLE results, this zeotropic binary mixture exhibits a positive deviation from Raoult’s law. Furthermore, the validated data are correlated with three activity coefficient models (i.e., Wilson, NRTL, and UNIQUAC), with the Wilson equation being the most accurate one. Excess volumes, surface tensions, and liquid viscosities data are correlated by Redlich–Kister-type expansions, and the Grunberg–Nissan equation is also applied to viscosity modeling. The calculated excess volumes display a positive deviation from the ideal solution model. Regarding surface tensions, this system showcases both negative and positive deviation, althouhg slight, from the linear behavior while exhibiting the linear trend at a molar fraction of methyl butyrate of 0.758. In addition, this bimodal deviation is adequately predicted by the Chunxi model with the Wilson parameters determined from the VLE data. Finally, the dynamic viscosities data obey a strictly monotonic mole dependence predicted by Eyring’s theory, although without high accuracy. These results also reflect some interesting phenomena related to competitive association effects, which are discussed.

A forecasting model with hybrid bidirectional long short-term memory for mooring line responses of semi-submersible offshore platforms

Semi-submersible offshore platforms are often produced in the deep sea far away from land, which results in high operating costs and difficult safety maintenance due to the harsh and complex working conditions. Adopting a neural network model for online accurate prediction of mooring tension of semi-submersible offshore platforms can adjust the ballast according to the advance of mooring tension change to keep the platform in a relatively smooth movement amplitude and improve production efficiency. In addition, it can also prevent catastrophic accidents caused by anchor chain breakage due to excessive mooring tension. However, the measured mooring tension of semi-submersible offshore platforms is characterized by complex nonlinear non-stationarity, which leads to insufficient prediction accuracy of a single prediction model. This paper develops a novel online prediction model of mooring tension for semi-submersible offshore platforms based on empirical modal decomposition (EMD), convolutional neural network (CNN), and bidirectional long and short-term memory neural network (BiLSTM). The proposed model is validated using the measured data of the first semi-submersible offshore platform in the South China Sea during operation. The experimental results show that the proposed model outperforms other comparative models currently mainstream for mooring tension prediction. In addition, the proposed method can also be used to predict complex nonlinear data in the field of ship and ocean engineering.

Comprehensive assessment of the results of zorba dance-based rehabilitation in patients after myocardial infarction

Abstract Introduction Dance movement engages global muscle sequences of the human body, improves physical performance, and helps reduce stress and excessive muscle tension. Dance exercises allow you to better control your movement and muscles. Zorba Greek dancing as a form of physical activity brings benefits in the form of improved mental health, well-being and quality of life. Rehabilitation may contribute to improving cardiorespiratory fitness and mental condition in the group of patients after myocardial infarction. Aim of the study The aim of the study was to evaluate a rehabilitation program based on Zorba dance on selected clinical parameters in patients after myocardial infarction. Materials and methods The study included 99 patients after myocardial infarction who were rehabilitated for 5 weeks. Patients were enrolled into two groups. Group I (50 patients) performed cycle ergometer training and the Greek dance Zorba. Group II (49 patients) performed cycle ergometer training and rehabilitation exercises. At the beginning and after rehabilitation, patients' BMI, balance (scales: Tinetti, Berg, 30CST), gait (6MWT), psychophysical status (SF-36, WHO-5, FCIS), and breathlessness (mMRC scale) were assessed. Results After undergoing rehabilitation, there was a reduction in BMI (I vs. II p<0.01), improvement in balance on the Tinetti (I vs. II p<0.01) and Berg scale (I vs. II p<0.01), improvement in the 30CS test score (I vs. II p= 0.018), improvement in WHO-5 (I vs. II p< 0.01), and reduction in dyspnea (mMRC) (I vs. II p< 0.01) in the Zorba group. Conclusions Both methods of rehabilitation improve functional efficiency; However, rehabilitation with the use of Zorba dance additionally improves balance in patients after myocardial infarction.

Anastomotic tension "Bridging": a risk factor for anastomotic leakage following low anterior resection.

Excessive tension at the anastomosis contributes to anastomotic leakage (AL) in low anterior resection (LAR). However, the specific tension has not been measured. We assessed whether "Bridging," characterized by the proximal colon resembling a suspension bridge above the pelvic floor, is a significant risk factor for AL following LAR for rectal cancer. This retrospective study reviewed the medical records and laparoscopic videos of 102 patients who underwent laparoscopic LAR using the double stapling technique at Yachiyo Hospital between January 2014 and December 2023. Patients were classified based on whether they had Bridging (tight or sagging) or were in a Resting state of the proximal colon, and the association between Bridging and AL was examined. AL occurred in 31.3% of the Tight Bridging group, 20% of the Sagging Bridging group, and 2.2% of the Resting group (P = 0.002). The incidence of AL was significantly higher in patients with Bridging than in those without (23.2% vs. 2.2%, P = 0.003). Multivariate analysis revealed that Bridging is an independent risk factor for AL (odds ratio = 6.97; 95% confidence interval: 1.45-33.6; P = 0.016). The presence of Bridging is a significant risk factor for AL following LAR for rectal cancer, suggesting the need for implementing preventive measures in patients with this condition.

FPSO/LNG hawser system lifetime assessment by Gaidai multivariate risk assessment method

Floating Production Storage and Offloading (FPSO) unit being an offshore vessel, storing and producing crude oil, prior to crude oil being transported by accompanying shuttle tanker. Critical mooring/hawser strains during offloading operation have to be accurately predicted, in order to maintain operational safety and reliability. During certain types of offloading, excessive hawser tensions may occur, causing operational risks. Current study examines FPSO vessel’s dynamic reactions to hydrodynamic wave-induced loads, given realistic in situ environmental conditions, utilizing the AQWA software package. Current study advocates novel multi-dimensional spatiotemporal risks assessment approach, that is particularly well suited for large dataset analysis, based on numerical simulations (or measurements). Advocated multivariate reliability methodology may be useful for a variety of marine and offshore systems that must endure severe environmental stressors during their intended operational lifespan. Methodology, presented in this study provides advanced capability to efficiently, yet accurately evaluate dynamic system failure, hazard and damage risks, given representative dynamic record of multidimensional system’s inter-correlated critical components. Gaidai risk assessment method being novel dynamic multidimensional system’s lifetime assessment methodology. In order to validate and benchmark Gaidai risk assessment method, in this study it was applied to FPSO and potentially LNG (i.e., Liquid Natural Gas) vessels dynamics. Major advantage of the advocated approach is that there are no existing alternative risk assessment methods, able to tackle unlimited number of system’s dimensions. Accurate multi-dimensional risk assessment had been carried out, based on numerically simulated data, partially verified by available laboratory experiments. Confidence intervals had been given for predicted dynamic high-dimensional system risk levels.

A Study on the Impact of Low-Frequency Random Loading and Unloading on Silo Structures

To investigate the development of cracks in the walls of reinforced concrete silos under feeding–discharge cycle loading, their causes, and their fatigue life during dynamic loading, a study was conducted using a combination of in situ monitoring and numerical simulation analysis. The following conclusions were drawn: during the loading and unloading process of the silo, the time of occurrence of the minimum pressure points follows a 4:3 ratio; extreme points are approximately 15 min apart; the minimum pressure increases during material addition and decreases during material subtraction; and the load in the non-discharge area is 1.43 times that of the load in the discharge area. That is, at the same elevation, the load borne by the silo wall is uneven, with fluctuations and rotational effects occurring. Under such uneven load conditions, the silo wall experiences significant bending and torsional moments, causing excessive local tension and leading to cracking. Our analysis showed that the most unfavorable load condition occurs when discharge ports 5 and 7 are operating simultaneously, which causes the maximum tensile damage to the silo wall. For the first time, a fatigue life prediction model for reinforced concrete silos was proposed, and the accuracy of this prediction method was verified based on actual conditions.

Use of acoustic myography in evaluation of biceps brachii and triceps brachii muscle function in nine skijoring dogs

Abstract Studies have found pain and inflammation in the shoulder region of working sled dogs. As skijoring is a comparable, competitive winter sport, this act may result in injuries similar to those seen in sled dogs. The purpose of this study was to assess the duration of muscle contraction, temporal, and spatial summation (E-, S-, and T-scores) of the biceps and triceps brachii muscles and compare between skijoring and free-running. Nine skijoring dogs completed a free-run and skijoring trial on the same trail in random order. Acoustic myography (AMG), measuring on:off ratio (E-score), spatial summation (S-score), and temporal summation (T-score) of the biceps and triceps brachii was performed comparing the muscle work during skijoring and free-running tasks ensuring minimal acceleration during each recording period. Statistical analyses included Shapiro-Wilk tests, paired Student’s t-tests, two-way ANOVAs, and Mann-Whitney U tests. Significance was set at . When comparing the E-, S- and T-scores of the experienced dogs, the E-score of the triceps brachii was significantly lower during skijoring compared to free-running. When comparing the biceps versus the triceps in all dogs, T-score for the biceps was significantly lower than that of the triceps during skijoring. Males were significantly faster than the females during both the free-running and skijoring tasks. Males all fell in the experienced dog group. In experienced dogs, the increase in triceps workload during the task of skijoring with no apparent change in its antagonist, the biceps, could result in excess tension on the musculotendinous unit of the biceps. The relative workload of the biceps versus the triceps appears higher regarding temporal summation during skijoring.